Vulvodynia is a chronic, painful disorder of the vulvar region that affects 3-18 percent of women in the United States. Most research on this disease has been cross-sectional in design, and has focused on women referred to vulvodynia specialty clinics. Hence, little is known about the natural history of this disorder or the risk factors associated with its occurrence, persistence, or resolution in a general population. A number of genetic characteristics have been found to be associated with chronic pain syndromes in general [Catechol-O-Methyltransferase (COMT) and Nerve Growth Factor receptors (NGF-r)], and vulvodynia in particular [Interleukin-1 receptor antagonist (IL1RN) and melanocortin-1 receptor (MC1R)]. Similarly, hormonal exposures of women have been associated with the presence of vulvodynia and with pain sensitivity of the vulva, but results have been inconsistent. Assessment of genetic susceptibility in conjunction with hormonal factors, in order to assess gene-environment interaction, is imperative to further clarify the impact of these factors on the incidence, persistence, and remission of this morbid disorder. We hypothesize that an increased prevalence of one or more of the pain-associated genetic polymorphisms mentioned above will be present in women with vulvodynia, and that the risk of the onset, persistence, and remission of vulvodynia in these women will be influenced by previous and current exogenous hormone use, such as oral contraceptive and hormone therapy. Using a longitudinal prospective population-based study design, we propose to evaluate the prevalence, incidence, persistence, and remission rates of vulvodynia among a population-based, geographically defined group of 2500 women. Our specific aims are 1) to assess the prevalence, incidence, persistence, and remission rates of vulvodynia among these women, with clinical confirmation and DNA analysis in all women reporting current or past vulvodynia, in a representative subset of asymptomatic controls, and in all women reporting new or resolved vulvar symptoms during the study, and 2) to determine the association between pain-related genetic polymorphisms and exogenous hormone use, singly and in combination, with the incidence, persistence, and remission of vulvodynia via 2a) determining the prevalence of specific polymorphisms of candidate genes related to neuropathic pain (COMT, NGF-r, IL1RN, and MC1R) among these groups of women, 2b) assessing the associations between exogenous hormone use and the natural history of vulvodynia, and 2c) assessing gene-environment interactions between hormone exposure and genetic polymorphisms and their impact on the incidence, persistence, and remission of vulvodynia. Results from this study will substantially augment our understanding of the combined role of genetics and hormone exposure in the onset, maintenance, and remission of vulvodynia, facilitating future studies on pathophysiology, treatment, and prevention. PUBLIC HEALTH RELEVANCE: Results from this study will substantially augment our understanding of the combined role of genetics and hormone exposure in the onset, maintenance, and remission of vulvodynia, and will further direct our studies on pathophysiology, treatment, and prevention.